Each Family of Wing Chun or CMA in general has their own "Kuen Kuit"
拳訣 which is a translated in English as sometimes (Fist) song, poetry or I prefer the translation "formula". Which is a unique expression from each of our Ancestors on their training methodology, knowledge accumulated, understanding in general. The Kuen Kuit provide access into a decent understanding of the System itself, but take note the Kuen Kuit are generally transmitted in a more informal format, for instance during dim sum or tea house, but generally not in an academic sense.
Also to note Kuen Kuit are important concepts but are not & never will be the "be all end all" of Wing Chun, take them for what there worth but allow room to grow & accumulate your own understanding as well.
I would advise you to check out a book from "Moy Yat" called Kuen Kuit, haha since were on the topic, it gives a decent translation from the Kuen Kuit as handed down from Ip Man & inscribed on the chops.